The present invention relates to a DC motor of the type wherein brushes are attached to a rotor and a commutator is mountd on a casing.
The rotors of the prior art DC motors have been in general assembled by securely attaching a core to a rotary shaft and winding conductors on the core to form coils and connecting the ends of the coils to the segments of a commutator mounted on the rotary shaft for contact with brushes mounted on a casing. With the above construction, it has been considerably difficult to wind the coils on the core carried by the rotary shaft. Furthermore, the step for mounting the commutator on the rotary shaft and the step for connecting the coils with the commutator have been both very complex and cumbersome. The prior art DC motors have a further defect that they have been using carbon brushes, electrographitic brushes, metallic graphite brushes and so on so that wear and abrasion of the commutators are very rapid.